Various types of so-called navigation systems that perform guidance on a route from a present position to a destination designated by a user (particularly referred to as a driver in the description for in-vehicle navigation systems), have been developed and put into practical use. For example, standard in-vehicle navigation systems and the like determine momentarily changing road situations such as traffic jam or construction, dynamically change a route to an optimal route to the destination, and indicate the route.
Further, in Patent Literature 1, a navigation apparatus that retrieves and indicates, according to a destination inputted by a driver, a parking area near the destination, is disclosed. According to Patent Literature 1, a degree of congestion of a parking area (for example, closest to the destination) that has been firstly indicated is continuously checked, and, in a case where it is determined, while the vehicle is travelling, that a probability that this parking area is available is low, another parking area (for example, second-closest to the destination) is indicated.